DSP56857 datasheet(432/662 Pages) FREESCALE

432 / 662 page

HI8 Host Port

5685X Digital Signal Controller User Manual, Rev. 4

16-6

Freescale Semiconductor

HCS

(PB13)

Input

Input/Output

Disconnected

Internally

Host Chip Select—This is the chip select input for

the HI8.

Port B 13—This is a GPIO pin when not configured

for Host port use.

HREQ / HTRQ

HREQ

HTRQ

(PB14)

Open Drain

Output

Open Drain

Output

Input /Output

Disconnected

Internally

Host Request—When the HI8 is programmed for

HRMS = 0 functionality (typically used on a single

data strobe bus), this output is used by the HI8 to

request service from the Host Processor. The HREQ

may be connected to an interrupt request pin of a

Host Processor, a transfer request of a DMA

controller, or a control input of external circuitry.

Transmit Host Request—When the HI8 is

programmed for HRMS = 1 functionality (typically

used on a double data strobe bus), this signal is the

Transmit Host Request output (HTRQ). The HTRQ

may be connected to an interrupt request pin of a

Host Processor.

Port B 14—This is a GPIO pin when not configured

for Host port use.

HACK / HRRQ

HACK

HRRQ

(PB15)

Input

Open Drain

Output

Input /Output

Disconnected

Internally

Host Acknowledge—When the HI8 is programmed

for HRMS = 0 functionality (typically used on a single

data strobe bus), this input has two functions: 1)

provide a host acknowledge signal for DMA

transfers, or 2) to control handshaking and provide a

host interrupt acknowledge compatible with the

MC68000 family processors.

Receive Host Request—When the HI8 is

programmed for HRMA = 1 functionality (typically

used on a double data strobe bus), this signal is the

Receive Host Request output (HRRQ).

Port B 15—This is a GPIO pin when not configured

for Host port use.

Table 16-1.

Host Interface 8 Signals (Continued)

HI8 Port Pin

Signal Name

Signal Type

State During

Reset of Stop

Signal Description

DSP56857 Datasheet(PDF) 432 Page - Freescale Semiconductor, Inc

DSP56857 Datasheet(HTML) 432 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL